blob: 729d41d9ced389cb218feec8d02eb6feee6aae78 [file] [log] [blame]
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01001# Select 32 or 64 bit
2config 64BIT
Sam Ravnborg68409992007-11-17 15:37:31 +01003 bool "64-bit kernel" if ARCH = "x86"
David Woodhouseffee0de2012-12-20 21:51:55 +00004 default ARCH != "i386"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01005 ---help---
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01006 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
Jan Beulich3120e252012-09-10 12:41:45 +010010 def_bool y
11 depends on !64BIT
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010012
13config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010014 def_bool y
15 depends on 64BIT
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010016
17### Arch settings
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010018config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010019 def_bool y
Ingo Molnar6471b822015-06-03 10:00:13 +020020 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Stephen Boyd446f24d2013-04-30 15:28:42 -070026 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
Dan Williams21266be2015-11-19 18:19:29 -080027 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020028 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070029 select ARCH_HAS_FAST_MULTIPLIER
Riku Voipio957e3fa2014-12-12 16:57:44 -080030 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070031 select ARCH_HAS_KCOV if X86_64
Dan Williams96601ad2015-08-24 18:29:38 -040032 select ARCH_HAS_PMEM_API if X86_64
Ross Zwisler67a3e8f2015-08-27 13:14:20 -060033 select ARCH_HAS_MMIO_FLUSH
Ingo Molnar6471b822015-06-03 10:00:13 +020034 select ARCH_HAS_SG_CHAIN
Andrey Ryabininc6d30852016-01-20 15:00:55 -080035 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020036 select ARCH_HAVE_NMI_SAFE_CMPXCHG
37 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040038 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080039 select ARCH_MIGHT_HAVE_PC_SERIO
Ingo Molnar6471b822015-06-03 10:00:13 +020040 select ARCH_SUPPORTS_ATOMIC_RMW
Mel Gorman3b242c62015-06-30 14:57:13 -070041 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
Ingo Molnar6471b822015-06-03 10:00:13 +020042 select ARCH_SUPPORTS_INT128 if X86_64
43 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
44 select ARCH_USE_BUILTIN_BSWAP
45 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
46 select ARCH_USE_QUEUED_RWLOCKS
47 select ARCH_USE_QUEUED_SPINLOCKS
Mel Gorman72b252a2015-09-04 15:47:32 -070048 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
Ingo Molnar5aaeb5c2015-07-17 12:28:12 +020049 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Ingo Molnarda4276b2009-01-07 11:05:10 +010050 select ARCH_WANT_FRAME_POINTERS
Ingo Molnar6471b822015-06-03 10:00:13 +020051 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
52 select ARCH_WANT_OPTIONAL_GPIOLIB
53 select BUILDTIME_EXTABLE_SORT
54 select CLKEVT_I8253
55 select CLKSRC_I8253 if X86_32
56 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
57 select CLOCKSOURCE_WATCHDOG
58 select CLONE_BACKWARDS if X86_32
59 select COMPAT_OLD_SIGACTION if IA32_EMULATION
60 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070061 select EDAC_ATOMIC_SCRUB
62 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020063 select GENERIC_CLOCKEVENTS
64 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
65 select GENERIC_CLOCKEVENTS_MIN_ADJUST
66 select GENERIC_CMOS_UPDATE
67 select GENERIC_CPU_AUTOPROBE
68 select GENERIC_EARLY_IOREMAP
69 select GENERIC_FIND_FIRST_BIT
70 select GENERIC_IOMAP
71 select GENERIC_IRQ_PROBE
72 select GENERIC_IRQ_SHOW
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_SMP_IDLE_THREAD
75 select GENERIC_STRNCPY_FROM_USER
76 select GENERIC_STRNLEN_USER
77 select GENERIC_TIME_VSYSCALL
78 select HAVE_ACPI_APEI if ACPI
79 select HAVE_ACPI_APEI_NMI if ACPI
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_AOUT if X86_32
82 select HAVE_ARCH_AUDITSYSCALL
83 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
84 select HAVE_ARCH_JUMP_LABEL
85 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
86 select HAVE_ARCH_KGDB
87 select HAVE_ARCH_KMEMCHECK
Daniel Cashman9e08f572016-01-14 15:20:06 -080088 select HAVE_ARCH_MMAP_RND_BITS if MMU
89 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +020090 select HAVE_ARCH_SECCOMP_FILTER
91 select HAVE_ARCH_SOFT_DIRTY if X86_64
92 select HAVE_ARCH_TRACEHOOK
93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Daniel Borkmann60777762016-05-13 19:08:28 +020094 select HAVE_EBPF_JIT if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020095 select HAVE_CC_STACKPROTECTOR
96 select HAVE_CMPXCHG_DOUBLE
97 select HAVE_CMPXCHG_LOCAL
98 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -070099 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select HAVE_C_RECORDMCOUNT
101 select HAVE_DEBUG_KMEMLEAK
102 select HAVE_DEBUG_STACKOVERFLOW
103 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700104 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400105 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900106 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700107 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700108 select HAVE_EXIT_THREAD
Ingo Molnar6471b822015-06-03 10:00:13 +0200109 select HAVE_FENTRY if X86_64
110 select HAVE_FTRACE_MCOUNT_RECORD
111 select HAVE_FUNCTION_GRAPH_FP_TEST
112 select HAVE_FUNCTION_GRAPH_TRACER
113 select HAVE_FUNCTION_TRACER
114 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530115 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200116 select HAVE_IDE
117 select HAVE_IOREMAP_PROT
118 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
119 select HAVE_IRQ_TIME_ACCOUNTING
120 select HAVE_KERNEL_BZIP2
121 select HAVE_KERNEL_GZIP
122 select HAVE_KERNEL_LZ4
123 select HAVE_KERNEL_LZMA
124 select HAVE_KERNEL_LZO
125 select HAVE_KERNEL_XZ
126 select HAVE_KPROBES
127 select HAVE_KPROBES_ON_FTRACE
128 select HAVE_KRETPROBES
129 select HAVE_KVM
130 select HAVE_LIVEPATCH if X86_64
131 select HAVE_MEMBLOCK
132 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200133 select HAVE_MIXED_BREAKPOINTS_REGS
Petr Mladek42a0bb32016-05-20 17:00:33 -0700134 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200135 select HAVE_OPROFILE
136 select HAVE_OPTPROBES
137 select HAVE_PCSPKR_PLATFORM
138 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200139 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200140 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200141 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200142 select HAVE_REGS_AND_STACK_ACCESS_API
143 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400144 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200145 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300146 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100147 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200148 select MODULES_USE_ELF_RELA if X86_64
149 select MODULES_USE_ELF_REL if X86_32
150 select OLD_SIGACTION if X86_32
151 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
152 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500153 select RTC_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200154 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500155 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200156 select SYSCTL_EXCEPTION_TRACE
157 select USER_STACKTRACE_SUPPORT
158 select VIRT_TO_BUS
159 select X86_DEV_DMA_OPS if X86_64
160 select X86_FEATURE_NAMES if PROC_FS
Josh Poimboeufd4883d52016-02-28 22:22:43 -0600161 select HAVE_STACK_VALIDATION if X86_64
Dave Hansen63c17fb2016-02-12 13:02:08 -0800162 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen66d37572016-02-12 13:02:32 -0800163 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530164
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200165config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100166 def_bool y
167 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200168
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700169config OUTPUT_FORMAT
170 string
171 default "elf32-i386" if X86_32
172 default "elf64-x86-64" if X86_64
173
Sam Ravnborg73531902008-05-25 23:03:18 +0200174config ARCH_DEFCONFIG
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200175 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200176 default "arch/x86/configs/i386_defconfig" if X86_32
177 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200178
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100179config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100180 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100181
182config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100183 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100184
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100185config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100186 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100187
Daniel Cashman9e08f572016-01-14 15:20:06 -0800188config ARCH_MMAP_RND_BITS_MIN
189 default 28 if 64BIT
190 default 8
191
192config ARCH_MMAP_RND_BITS_MAX
193 default 32 if 64BIT
194 default 16
195
196config ARCH_MMAP_RND_COMPAT_BITS_MIN
197 default 8
198
199config ARCH_MMAP_RND_COMPAT_BITS_MAX
200 default 16
201
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100202config SBUS
203 bool
204
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800205config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100206 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400207 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800208
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700209config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700210 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700211
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100212config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100213 def_bool y
214 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100215
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100216config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100217 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100218 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000219 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
220
221config GENERIC_BUG_RELATIVE_POINTERS
222 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100223
224config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100225 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100226
227config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100228 def_bool y
229 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100230
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100231config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100232 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100233
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100234config GENERIC_CALIBRATE_DELAY
235 def_bool y
236
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800237config ARCH_HAS_CPU_RELAX
238 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100239
Pekka Enberg1b27d052008-04-28 02:12:22 -0700240config ARCH_HAS_CACHE_LINE_SIZE
241 def_bool y
242
Mike Travisdd5af902008-01-30 13:33:32 +0100243config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900244 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100245
Tejun Heo08fc4582009-08-14 15:00:49 +0900246config NEED_PER_CPU_EMBED_FIRST_CHUNK
247 def_bool y
248
249config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900250 def_bool y
251
Johannes Berg801e4062007-12-08 02:12:39 +0100252config ARCH_HIBERNATION_POSSIBLE
253 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100254
Johannes Bergf4cb5702007-12-08 02:14:00 +0100255config ARCH_SUSPEND_POSSIBLE
256 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100257
Steve Cappercfe28c52013-04-29 14:29:48 +0100258config ARCH_WANT_HUGE_PMD_SHARE
259 def_bool y
260
Steve Capper53313b22013-04-30 08:03:42 +0100261config ARCH_WANT_GENERAL_HUGETLB
262 def_bool y
263
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100264config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000265 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100266
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100267config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000268 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100269
Ingo Molnar765c68b2008-04-09 11:03:37 +0200270config ARCH_SUPPORTS_OPTIMIZED_INLINING
271 def_bool y
272
Akinobu Mita6a11f752009-03-31 15:23:17 -0700273config ARCH_SUPPORTS_DEBUG_PAGEALLOC
274 def_bool y
275
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300276config KASAN_SHADOW_OFFSET
277 hex
278 depends on KASAN
279 default 0xdffffc0000000000
280
Shane Wang69575d32009-09-01 18:25:07 -0700281config HAVE_INTEL_TXT
282 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700283 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700284
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100285config X86_32_SMP
286 def_bool y
287 depends on X86_32 && SMP
288
289config X86_64_SMP
290 def_bool y
291 depends on X86_64 && SMP
292
Tejun Heoccbeed32009-02-09 22:17:40 +0900293config X86_32_LAZY_GS
294 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900295 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900296
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530297config ARCH_SUPPORTS_UPROBES
298 def_bool y
299
Rob Herringd20642f2014-04-18 17:19:54 -0500300config FIX_EARLYCON_MEM
301 def_bool y
302
Kees Cook9ccaf772016-02-17 14:41:14 -0800303config DEBUG_RODATA
304 def_bool y
305
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700306config PGTABLE_LEVELS
307 int
308 default 4 if X86_64
309 default 3 if X86_PAE
310 default 2
311
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100312source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700313source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100314
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100315menu "Processor type and features"
316
Randy Dunlap5ee71532012-01-16 11:57:18 -0800317config ZONE_DMA
318 bool "DMA memory allocation support" if EXPERT
319 default y
320 help
321 DMA memory allocation support allows devices with less than 32-bit
322 addressing to allocate within the first 16MB of address space.
323 Disable if no such devices will be used.
324
325 If unsure, say Y.
326
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100327config SMP
328 bool "Symmetric multi-processing support"
329 ---help---
330 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800331 a system with only one CPU, say N. If you have a system with more
332 than one CPU, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100333
Robert Graffham4a474152014-01-23 15:55:29 -0800334 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100335 machines, but will use only one CPU of a multiprocessor machine. If
336 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800337 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100338 will run faster if you say N here.
339
340 Note that if you say Y here and choose architecture "586" or
341 "Pentium" under "Processor family", the kernel will not work on 486
342 architectures. Similarly, multiprocessor kernels for the "PPro"
343 architecture may not work on all Pentium based boards.
344
345 People using multiprocessor machines who say Y here should also say
346 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
347 Management" code will be disabled if you say Y here.
348
Paul Bolle395cf962011-08-15 02:02:26 +0200349 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100350 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
351 <http://www.tldp.org/docs.html#howto>.
352
353 If you don't know what to do here, say N.
354
Josh Triplett9def39be2013-10-30 08:09:45 -0700355config X86_FEATURE_NAMES
356 bool "Processor feature human-readable names" if EMBEDDED
357 default y
358 ---help---
359 This option compiles in a table of x86 feature bits and corresponding
360 names. This is required to support /proc/cpuinfo and a few kernel
361 messages. You can disable this to save space, at the expense of
362 making those few kernel messages show numeric feature bits instead.
363
364 If in doubt, say Y.
365
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100366config X86_FAST_FEATURE_TESTS
367 bool "Fast CPU feature tests" if EMBEDDED
368 default y
369 ---help---
370 Some fast-paths in the kernel depend on the capabilities of the CPU.
371 Say Y here for the kernel to patch in the appropriate code at runtime
372 based on the capabilities of the CPU. The infrastructure for patching
373 code at runtime takes up some additional space; space-constrained
374 embedded systems may wish to say N here to produce smaller, slightly
375 slower code.
376
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800377config X86_X2APIC
378 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200379 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800380 ---help---
381 This enables x2apic support on CPUs that have this feature.
382
383 This allows 32-bit apic IDs (so it can support very large systems),
384 and accesses the local apic via MSRs not via mmio.
385
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800386 If you don't know what to do here, say N.
387
Yinghai Lu6695c852008-06-19 12:13:09 -0700388config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700389 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000390 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200391 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100392 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700393 For old smp systems that do not have proper acpi support. Newer systems
394 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700395
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800396config X86_BIGSMP
397 bool "Support for big SMP systems with more than 8 CPUs"
398 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100399 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800400 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100401
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000402config GOLDFISH
403 def_bool y
404 depends on X86_GOLDFISH
405
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800406if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800407config X86_EXTENDED_PLATFORM
408 bool "Support for extended (non-PC) x86 platforms"
409 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100410 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100411 If you disable this option then the kernel will only support
412 standard PC platforms. (which covers the vast majority of
413 systems out there.)
414
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800415 If you enable this option then you'll be able to select support
416 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100417 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800418 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800419 RDC R-321x SoC
420 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200421 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200422 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100423
424 If you have one of these systems, or if you want to build a
425 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800426endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100427
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800428if X86_64
429config X86_EXTENDED_PLATFORM
430 bool "Support for extended (non-PC) x86 platforms"
431 default y
432 ---help---
433 If you disable this option then the kernel will only support
434 standard PC platforms. (which covers the vast majority of
435 systems out there.)
436
437 If you enable this option then you'll be able to select support
438 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b2011-12-06 00:07:26 +0800439 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800440 ScaleMP vSMP
441 SGI Ultraviolet
442
443 If you have one of these systems, or if you want to build a
444 generic distribution kernel, say Y here - otherwise say N.
445endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800446# This is an alphabetically sorted list of 64 bit extended platforms
447# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b2011-12-06 00:07:26 +0800448config X86_NUMACHIP
449 bool "Numascale NumaChip"
450 depends on X86_64
451 depends on X86_EXTENDED_PLATFORM
452 depends on NUMA
453 depends on SMP
454 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700455 depends on PCI_MMCONFIG
Steffen Persvold44b111b2011-12-06 00:07:26 +0800456 ---help---
457 Adds support for Numascale NumaChip large-SMP systems. Needed to
458 enable more than ~168 cores.
459 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100460
Ingo Molnar6a485652009-01-27 18:29:13 +0100461config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800462 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100463 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100464 select PARAVIRT
465 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800466 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300467 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100468 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100469 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
470 supposed to run on these EM64T-based machines. Only choose this option
471 if you have one of these machines.
472
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800473config X86_UV
474 bool "SGI Ultraviolet"
475 depends on X86_64
476 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500477 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800478 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700479 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200480 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800481 ---help---
482 This option is needed in order to support SGI Ultraviolet systems.
483 If you don't have one of these, you should say N here.
484
485# Following is an alphabetically sorted list of 32 bit extended platforms
486# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100487
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000488config X86_GOLDFISH
489 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100490 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000491 ---help---
492 Enable support for the Goldfish virtual platform used primarily
493 for Android development. Unless you are building for the Android
494 Goldfish emulator say N here.
495
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800496config X86_INTEL_CE
497 bool "CE4100 TV platform"
498 depends on PCI
499 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800500 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800501 depends on X86_32
502 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800503 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100504 select OF
505 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800506 ---help---
507 Select for the Intel CE media processor (CE4100) SOC.
508 This option compiles in support for the CE4100 SOC for settop
509 boxes and media devices.
510
David Cohen4cb9b002013-12-16 17:37:26 -0800511config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100512 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100513 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800514 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000515 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200516 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000517 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000518 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800519 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000520 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000521 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000522 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000523 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000524 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800525 Select to build a kernel capable of supporting Intel MID (Mobile
526 Internet Device) platform systems which do not have the PCI legacy
527 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000528
David Cohen4cb9b002013-12-16 17:37:26 -0800529 Intel MID platforms are based on an Intel processor and chipset which
530 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100531
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000532config X86_INTEL_QUARK
533 bool "Intel Quark platform support"
534 depends on X86_32
535 depends on X86_EXTENDED_PLATFORM
536 depends on X86_PLATFORM_DEVICES
537 depends on X86_TSC
538 depends on PCI
539 depends on PCI_GOANY
540 depends on X86_IO_APIC
541 select IOSF_MBI
542 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200543 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000544 ---help---
545 Select to include support for Quark X1000 SoC.
546 Say Y here if you have a Quark based system such as the Arduino
547 compatible Intel Galileo.
548
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000549config X86_INTEL_LPSS
550 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100551 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000552 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300553 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100554 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000555 ---help---
556 Select to build support for Intel Low Power Subsystem such as
557 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300558 things like clock tree (common clock framework) and pincontrol
559 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000560
Ken Xue92082a82015-02-06 08:27:51 +0800561config X86_AMD_PLATFORM_DEVICE
562 bool "AMD ACPI2Platform devices support"
563 depends on ACPI
564 select COMMON_CLK
565 select PINCTRL
566 ---help---
567 Select to interpret AMD specific ACPI device to platform device
568 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
569 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
570 implemented under PINCTRL subsystem.
571
David E. Boxced3ce72014-09-17 22:13:50 -0700572config IOSF_MBI
573 tristate "Intel SoC IOSF Sideband support for SoC platforms"
574 depends on PCI
575 ---help---
576 This option enables sideband register access support for Intel SoC
577 platforms. On these platforms the IOSF sideband is used in lieu of
578 MSR's for some register accesses, mostly but not limited to thermal
579 and power. Drivers may query the availability of this device to
580 determine if they need the sideband in order to work on these
581 platforms. The sideband is available on the following SoC products.
582 This list is not meant to be exclusive.
583 - BayTrail
584 - Braswell
585 - Quark
586
587 You should say Y if you are running a kernel on one of these SoC's.
588
David E. Boxed2226b2014-09-17 22:13:51 -0700589config IOSF_MBI_DEBUG
590 bool "Enable IOSF sideband access through debugfs"
591 depends on IOSF_MBI && DEBUG_FS
592 ---help---
593 Select this option to expose the IOSF sideband access registers (MCR,
594 MDR, MCRX) through debugfs to write and read register information from
595 different units on the SoC. This is most useful for obtaining device
596 state information for debug and analysis. As this is a general access
597 mechanism, users of this option would have specific knowledge of the
598 device they want to access.
599
600 If you don't require the option or are in doubt, say N.
601
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800602config X86_RDC321X
603 bool "RDC R-321x SoC"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100604 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800605 depends on X86_EXTENDED_PLATFORM
606 select M486
607 select X86_REBOOTFIXUPS
608 ---help---
609 This option is needed for RDC R-321x system-on-chip, also known
610 as R-8610-(G).
611 If you don't have one of these chips, you should say N here.
612
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100613config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100614 bool "Support non-standard 32-bit SMP architectures"
615 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800616 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100617 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800618 This option compiles in the bigsmp and STA2X11 default
619 subarchitectures. It is intended for a generic binary
620 kernel. If you select them all, kernel will probe it one by
621 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700622
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800623# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700624
Linus Torvaldsd949f362009-09-26 09:35:07 -0700625config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100626 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700627 # MCE code calls memory_failure():
628 depends on X86_MCE
629 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700630 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
631 depends on X86_64 || !SPARSEMEM
632 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700633
Alessandro Rubini83125a32012-04-04 19:40:21 +0200634config STA2X11
635 bool "STA2X11 Companion Chip Support"
636 depends on X86_32_NON_STANDARD && PCI
637 select X86_DEV_DMA_OPS
638 select X86_DMA_REMAP
639 select SWIOTLB
640 select MFD_STA2X11
641 select ARCH_REQUIRE_GPIOLIB
642 default n
643 ---help---
644 This adds support for boards based on the STA2X11 IO-Hub,
645 a.k.a. "ConneXt". The chip is used in place of the standard
646 PC chipset, so all "standard" peripherals are missing. If this
647 option is selected the kernel will still be able to boot on
648 standard PC machines.
649
Shérab82148d12010-09-25 06:06:57 +0200650config X86_32_IRIS
651 tristate "Eurobraille/Iris poweroff module"
652 depends on X86_32
653 ---help---
654 The Iris machines from EuroBraille do not have APM or ACPI support
655 to shut themselves down properly. A special I/O sequence is
656 needed to do so, which is what this module does at
657 kernel shutdown.
658
659 This is only for Iris machines from EuroBraille.
660
661 If unused, say N.
662
Ingo Molnarae1e9132008-11-11 09:05:16 +0100663config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100664 def_bool y
665 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800666 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100667 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100668 Calculate simpler /proc/<PID>/wchan values. If this option
669 is disabled then wchan values will recurse back to the
670 caller function. This provides more accurate wchan values,
671 at the expense of slightly more scheduling overhead.
672
673 If in doubt, say "Y".
674
Borislav Petkov6276a072013-03-04 21:20:21 +0100675menuconfig HYPERVISOR_GUEST
676 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100677 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100678 Say Y here to enable options for running Linux under various hyper-
679 visors. This option enables basic hypervisor detection and platform
680 setup.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100681
Borislav Petkov6276a072013-03-04 21:20:21 +0100682 If you say N, all options in this submenu will be skipped and
683 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100684
Borislav Petkov6276a072013-03-04 21:20:21 +0100685if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100686
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100687config PARAVIRT
688 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100689 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100690 This changes the kernel so it can modify itself when it is run
691 under a hypervisor, potentially improving performance significantly
692 over full virtualization. However, when run without a hypervisor
693 the kernel is theoretically slower and slightly larger.
694
Borislav Petkov6276a072013-03-04 21:20:21 +0100695config PARAVIRT_DEBUG
696 bool "paravirt-ops debugging"
697 depends on PARAVIRT && DEBUG_KERNEL
698 ---help---
699 Enable to debug paravirt_ops internals. Specifically, BUG if
700 a paravirt_op is missing when it is called.
701
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700702config PARAVIRT_SPINLOCKS
703 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700704 depends on PARAVIRT && SMP
Ingo Molnar62c7a1e2015-05-11 09:47:23 +0200705 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700706 ---help---
707 Paravirtualized spinlocks allow a pvops backend to replace the
708 spinlock implementation with something virtualization-friendly
709 (for example, block the virtual CPU rather than spinning).
710
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530711 It has a minimal impact on native kernels and gives a nice performance
712 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700713
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530714 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700715
Waiman Long45e898b2015-11-09 19:09:25 -0500716config QUEUED_LOCK_STAT
717 bool "Paravirt queued spinlock statistics"
718 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
719 ---help---
720 Enable the collection of statistical data on the slowpath
721 behavior of paravirtualized queued spinlocks and report
722 them on debugfs.
723
Borislav Petkov6276a072013-03-04 21:20:21 +0100724source "arch/x86/xen/Kconfig"
725
726config KVM_GUEST
727 bool "KVM Guest support (including kvmclock)"
728 depends on PARAVIRT
729 select PARAVIRT_CLOCK
730 default y
731 ---help---
732 This option enables various optimizations for running under the KVM
733 hypervisor. It includes a paravirtualized clock, so that instead
734 of relying on a PIT (or probably other) emulation by the
735 underlying device model, the host provides the guest with
736 timing infrastructure such as time of day, and system time
737
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530738config KVM_DEBUG_FS
739 bool "Enable debug information for KVM Guests in debugfs"
740 depends on KVM_GUEST && DEBUG_FS
741 default n
742 ---help---
743 This option enables collection of various statistics for KVM guest.
744 Statistics are displayed in debugfs filesystem. Enabling this option
745 may incur significant overhead.
746
Borislav Petkov6276a072013-03-04 21:20:21 +0100747source "arch/x86/lguest/Kconfig"
748
749config PARAVIRT_TIME_ACCOUNTING
750 bool "Paravirtual steal time accounting"
751 depends on PARAVIRT
752 default n
753 ---help---
754 Select this option to enable fine granularity task steal time
755 accounting. Time spent executing other tasks in parallel with
756 the current vCPU is discounted from the vCPU power. To account for
757 that, there can be a small performance impact.
758
759 If in doubt, say N here.
760
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200761config PARAVIRT_CLOCK
762 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200763
Borislav Petkov6276a072013-03-04 21:20:21 +0100764endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400765
Yinghai Lu08677212010-02-10 01:20:20 -0800766config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700767 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800768
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100769source "arch/x86/Kconfig.cpu"
770
771config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100772 def_bool X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100773 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100774 ---help---
775 Use the IA-PC HPET (High Precision Event Timer) to manage
776 time in preference to the PIT and RTC, if a HPET is
777 present.
778 HPET is the next generation timer replacing legacy 8254s.
779 The HPET provides a stable time base on SMP
780 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200781 as it is off-chip. The interface used is documented
782 in the HPET spec, revision 1.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100783
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100784 You can safely choose Y here. However, HPET will only be
785 activated if the platform and the BIOS support this feature.
786 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100787
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100788 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100789
790config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100791 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800792 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100793
Jacob Panbb24c472009-09-02 07:37:17 -0700794config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000795 def_bool y if X86_INTEL_MID
796 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100797 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000798 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700799 help
800 APB timer is the replacement for 8254, HPET on X86 MID platforms.
801 The APBT provides a stable time base on SMP
802 systems, unlike the TSC, but it is more expensive to access,
803 as it is off-chip. APB timers are always running regardless of CPU
804 C states, they are used as per CPU clockevent device when possible.
805
David Rientjes6a108a12011-01-20 14:44:16 -0800806# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100807# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700808config DMI
809 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800810 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800811 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100812 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700813 Enabled scanning of DMI to identify machine quirks. Say Y
814 here unless you have verified that your setup is not
815 affected by entries in the DMI blacklist. Required by PNP
816 BIOS code.
817
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100818config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700819 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100820 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200821 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100822 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200823 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
824 GART based hardware IOMMUs.
825
826 The GART supports full DMA access for devices with 32-bit access
827 limitations, on systems with more than 3 GB. This is usually needed
828 for USB, sound, many IDE/SATA chipsets and some other devices.
829
830 Newer systems typically have a modern AMD IOMMU, supported via
831 the CONFIG_AMD_IOMMU=y config option.
832
833 In normal configurations this driver is only active when needed:
834 there's more than 3 GB of memory and the system contains a
835 32-bit limited device.
836
837 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100838
839config CALGARY_IOMMU
840 bool "IBM Calgary IOMMU support"
841 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700842 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100843 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100844 Support for hardware IOMMUs in IBM's xSeries x366 and x460
845 systems. Needed to run systems with more than 3GB of memory
846 properly with 32-bit PCI devices that do not support DAC
847 (Double Address Cycle). Calgary also supports bus level
848 isolation, where all DMAs pass through the IOMMU. This
849 prevents them from going anywhere except their intended
850 destination. This catches hard-to-find kernel bugs and
851 mis-behaving drivers and devices that do not use the DMA-API
852 properly to set up their DMA buffers. The IOMMU can be
853 turned off at boot time with the iommu=off parameter.
854 Normally the kernel will make the right choice by itself.
855 If unsure, say Y.
856
857config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100858 def_bool y
859 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100860 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100861 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100862 Should Calgary be enabled by default? if you choose 'y', Calgary
863 will be used (if it exists). If you choose 'n', Calgary will not be
864 used even if it exists. If you choose 'n' and would like to use
865 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
866 If unsure, say Y.
867
868# need this always selected by IOMMU for the VIA workaround
869config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100870 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100871 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100872 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700873 which don't have a hardware IOMMU. Using this PCI devices
874 which can only access 32-bits of memory can be used on systems
875 with more than 3 GB of memory.
876 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100877
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700878config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100879 def_bool y
880 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700881
Mike Travis1184dc22008-05-12 21:21:12 +0200882config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200883 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700884 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800885 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100886 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200887 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200888 If unsure, say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100889
890config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800891 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400892 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500893 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500894 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800895 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500896 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800897 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300898 default "8" if SMP && X86_32
899 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100900 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100901 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500902 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300903 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100904 minimum value which makes sense is 2.
905
906 This is purely to save memory - each supported CPU adds
907 approximately eight kilobytes to the kernel image.
908
909config SCHED_SMT
910 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200911 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100912 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100913 SMT scheduler support improves the CPU scheduler's decision making
914 when dealing with Intel Pentium 4 chips with HyperThreading at a
915 cost of slightly increased overhead in some places. If unsure say
916 N here.
917
918config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100919 def_bool y
920 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200921 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100922 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100923 Multi-core scheduler support improves the CPU scheduler's decision
924 making when dealing with multi-core CPU chips at a cost of slightly
925 increased overhead in some places. If unsure say N here.
926
927source "kernel/Kconfig.preempt"
928
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000929config UP_LATE_INIT
930 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100931 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000932
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100933config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000934 bool "Local APIC support on uniprocessors" if !PCI_MSI
935 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000936 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100937 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100938 A local APIC (Advanced Programmable Interrupt Controller) is an
939 integrated interrupt controller in the CPU. If you have a single-CPU
940 system which has a processor with a local APIC, you can say Y here to
941 enable and use it. If you say Y here even though your machine doesn't
942 have a local APIC, then the kernel will still run with no slowdown at
943 all. The local APIC supports CPU-generated self-interrupts (timer,
944 performance counters), and the NMI watchdog which detects hard
945 lockups.
946
947config X86_UP_IOAPIC
948 bool "IO-APIC support on uniprocessors"
949 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100950 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100951 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
952 SMP-capable replacement for PC-style interrupt controllers. Most
953 SMP systems and many recent uniprocessor systems have one.
954
955 If you have a single-CPU system with an IO-APIC, you can say Y here
956 to use it. If you say Y here even though your machine doesn't have
957 an IO-APIC, then the kernel will still run with no slowdown at all.
958
959config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100960 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200961 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800962 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800963 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100964
965config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000966 def_bool y
967 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100968
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200969config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
970 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200971 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100972 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200973 This option enables a workaround that fixes a source of
974 spurious interrupts. This is recommended when threaded
975 interrupt handling is used on systems where the generation of
976 superfluous "boot interrupts" cannot be disabled.
977
978 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
979 entry in the chipset's IO-APIC is masked (as, e.g. the RT
980 kernel does during interrupt handling). On chipsets where this
981 boot IRQ generation cannot be disabled, this workaround keeps
982 the original IRQ line masked so that only the equivalent "boot
983 IRQ" is delivered to the CPUs. The workaround also tells the
984 kernel to set up the IRQ handler on the boot IRQ line. In this
985 way only one interrupt is delivered to the kernel. Otherwise
986 the spurious second interrupt may cause the kernel to bring
987 down (vital) interrupt lines.
988
989 Only affects "broken" chipsets. Interrupt sharing may be
990 increased on these systems.
991
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100992config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +0200993 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +0200994 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +0200995 default y
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100996 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +0200997 Machine Check support allows the processor to notify the
998 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100999 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001000 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001001
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001002config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001003 def_bool y
1004 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001005 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001006 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001007 Additional support for intel specific MCE features such as
1008 the thermal monitor.
1009
1010config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001011 def_bool y
1012 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001013 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001014 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001015 Additional support for AMD specific MCE features such as
1016 the DRAM Error Threshold.
1017
Andi Kleen4efc0672009-04-28 19:07:31 +02001018config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001019 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001020 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001021 ---help---
1022 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001023 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001024 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001025
Andi Kleenb2762682009-02-12 13:49:31 +01001026config X86_MCE_THRESHOLD
1027 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001028 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001029
Andi Kleenea149b32009-04-29 19:31:00 +02001030config X86_MCE_INJECT
Andi Kleenc1ebf832009-07-09 00:31:41 +02001031 depends on X86_MCE
Andi Kleenea149b32009-04-29 19:31:00 +02001032 tristate "Machine check injector support"
1033 ---help---
1034 Provide support for injecting machine checks for testing purposes.
1035 If you don't know what a machine check is and you don't do kernel
1036 QA it is safe to say n.
1037
Andi Kleen4efc0672009-04-28 19:07:31 +02001038config X86_THERMAL_VECTOR
1039 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001040 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001041
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001042source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001043
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001044config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001045 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001046 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001047 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001048 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001049 This option allows user programs to put the CPU into V8086
1050 mode, which is an 80286-era approximation of 16-bit real mode.
1051
1052 Some very old versions of X and/or vbetool require this option
1053 for user mode setting. Similarly, DOSEMU will use it if
1054 available to accelerate real mode DOS programs. However, any
1055 recent version of DOSEMU, X, or vbetool should be fully
1056 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001057 fall back to software emulation. Nevertheless, if you are using
1058 a 16-bit DOS program where 16-bit performance matters, vm86
1059 mode might be faster than emulation and you might want to
1060 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001061
Ingo Molnar1e642812015-09-05 08:58:10 +02001062 Note that any app that works on a 64-bit kernel is unlikely to
1063 need this option, as 64-bit kernels don't, and can't, support
1064 V8086 mode. This option is also unrelated to 16-bit protected
1065 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001066
Ingo Molnar1e642812015-09-05 08:58:10 +02001067 Enabling this option increases the complexity of the kernel
1068 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001069
Ingo Molnar1e642812015-09-05 08:58:10 +02001070 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001071
1072config VM86
1073 bool
1074 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001075
1076config X86_16BIT
1077 bool "Enable support for 16-bit segments" if EXPERT
1078 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001079 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001080 ---help---
1081 This option is required by programs like Wine to run 16-bit
1082 protected mode legacy code on x86 processors. Disabling
1083 this option saves about 300 bytes on i386, or around 6K text
1084 plus 16K runtime memory on x86-64,
1085
1086config X86_ESPFIX32
1087 def_bool y
1088 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001089
H. Peter Anvin197725d2014-05-04 10:00:49 -07001090config X86_ESPFIX64
1091 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001092 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001093
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001094config X86_VSYSCALL_EMULATION
1095 bool "Enable vsyscall emulation" if EXPERT
1096 default y
1097 depends on X86_64
1098 ---help---
1099 This enables emulation of the legacy vsyscall page. Disabling
1100 it is roughly equivalent to booting with vsyscall=none, except
1101 that it will also disable the helpful warning if a program
1102 tries to use a vsyscall. With this option set to N, offending
1103 programs will just segfault, citing addresses of the form
1104 0xffffffffff600?00.
1105
1106 This option is required by many programs built before 2013, and
1107 care should be used even with newer programs if set to N.
1108
1109 Disabling this option saves about 7K of kernel size and
1110 possibly 4K of additional runtime pagetable memory.
1111
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001112config TOSHIBA
1113 tristate "Toshiba Laptop support"
1114 depends on X86_32
1115 ---help---
1116 This adds a driver to safely access the System Management Mode of
1117 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1118 not work on models with a Phoenix BIOS. The System Management Mode
1119 is used to set the BIOS and power saving options on Toshiba portables.
1120
1121 For information on utilities to make use of this driver see the
1122 Toshiba Linux utilities web site at:
1123 <http://www.buzzard.org.uk/toshiba/>.
1124
1125 Say Y if you intend to run this kernel on a Toshiba portable.
1126 Say N otherwise.
1127
1128config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001129 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001130 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001131 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001132 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001133 This option enables legacy /proc/i8k userspace interface in hwmon
1134 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1135 temperature and allows controlling fan speeds of Dell laptops via
1136 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1137 it reports also power and hotkey status. For fan speed control is
1138 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001139
Pali Rohár039ae582015-05-14 13:16:37 +02001140 Say Y if you intend to run this kernel on old Dell laptops or want to
1141 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001142 Say N otherwise.
1143
1144config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001145 bool "Enable X86 board specific fixups for reboot"
1146 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001147 ---help---
1148 This enables chipset and/or board specific fixups to be done
1149 in order to get reboot to work correctly. This is only needed on
1150 some combinations of hardware and BIOS. The symptom, for which
1151 this config is intended, is when reboot ends with a stalled/hung
1152 system.
1153
1154 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001155 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001156
1157 Say Y if you want to enable the fixup. Currently, it's safe to
1158 enable this option even if you don't need it.
1159 Say N otherwise.
1160
1161config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001162 bool "CPU microcode loading support"
1163 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001164 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001165 select FW_LOADER
1166 ---help---
1167 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001168 Intel and AMD processors. The Intel support is for the IA32 family,
1169 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1170 AMD support is for families 0x10 and later. You will obviously need
1171 the actual microcode binary data itself which is not shipped with
1172 the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001173
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001174 The preferred method to load microcode from a detached initrd is described
1175 in Documentation/x86/early-microcode.txt. For that you need to enable
1176 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1177 initrd for microcode blobs.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001178
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001179 In addition, you can build-in the microcode into the kernel. For that you
1180 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1181 to the CONFIG_EXTRA_FIRMWARE config option.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001182
Peter Oruba8d86f392008-07-28 18:44:21 +02001183config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001184 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001185 depends on MICROCODE
1186 default MICROCODE
1187 select FW_LOADER
1188 ---help---
1189 This options enables microcode patch loading support for Intel
1190 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001191
Alanb8989db2014-01-20 18:01:56 +00001192 For the current Intel microcode data package go to
1193 <https://downloadcenter.intel.com> and search for
1194 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001195
Peter Oruba80cc9f12008-07-28 18:44:22 +02001196config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001197 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001198 depends on MICROCODE
1199 select FW_LOADER
1200 ---help---
1201 If you select this option, microcode patch loading support for AMD
1202 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001203
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001204config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001205 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001206 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001207
1208config X86_MSR
1209 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001210 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001211 This device gives privileged processes access to the x86
1212 Model-Specific Registers (MSRs). It is a character device with
1213 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1214 MSR accesses are directed to a specific CPU on multi-processor
1215 systems.
1216
1217config X86_CPUID
1218 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001219 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001220 This device gives processes access to the x86 CPUID instruction to
1221 be executed on a specific processor. It is a character device
1222 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1223 /dev/cpu/31/cpuid.
1224
1225choice
1226 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001227 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001228 depends on X86_32
1229
1230config NOHIGHMEM
1231 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001232 ---help---
1233 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1234 However, the address space of 32-bit x86 processors is only 4
1235 Gigabytes large. That means that, if you have a large amount of
1236 physical memory, not all of it can be "permanently mapped" by the
1237 kernel. The physical memory that's not permanently mapped is called
1238 "high memory".
1239
1240 If you are compiling a kernel which will never run on a machine with
1241 more than 1 Gigabyte total physical RAM, answer "off" here (default
1242 choice and suitable for most users). This will result in a "3GB/1GB"
1243 split: 3GB are mapped so that each process sees a 3GB virtual memory
1244 space and the remaining part of the 4GB virtual memory space is used
1245 by the kernel to permanently map as much physical memory as
1246 possible.
1247
1248 If the machine has between 1 and 4 Gigabytes physical RAM, then
1249 answer "4GB" here.
1250
1251 If more than 4 Gigabytes is used then answer "64GB" here. This
1252 selection turns Intel PAE (Physical Address Extension) mode on.
1253 PAE implements 3-level paging on IA32 processors. PAE is fully
1254 supported by Linux, PAE mode is implemented on all recent Intel
1255 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1256 then the kernel will not boot on CPUs that don't support PAE!
1257
1258 The actual amount of total physical memory will either be
1259 auto detected or can be forced by using a kernel command line option
1260 such as "mem=256M". (Try "man bootparam" or see the documentation of
1261 your boot loader (lilo or loadlin) about how to pass options to the
1262 kernel at boot time.)
1263
1264 If unsure, say "off".
1265
1266config HIGHMEM4G
1267 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001268 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001269 Select this if you have a 32-bit processor and between 1 and 4
1270 gigabytes of physical RAM.
1271
1272config HIGHMEM64G
1273 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001274 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001275 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001276 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001277 Select this if you have a 32-bit processor and more than 4
1278 gigabytes of physical RAM.
1279
1280endchoice
1281
1282choice
David Rientjes6a108a12011-01-20 14:44:16 -08001283 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001284 default VMSPLIT_3G
1285 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001286 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001287 Select the desired split between kernel and user memory.
1288
1289 If the address range available to the kernel is less than the
1290 physical memory installed, the remaining memory will be available
1291 as "high memory". Accessing high memory is a little more costly
1292 than low memory, as it needs to be mapped into the kernel first.
1293 Note that increasing the kernel address space limits the range
1294 available to user programs, making the address space there
1295 tighter. Selecting anything other than the default 3G/1G split
1296 will also likely make your kernel incompatible with binary-only
1297 kernel modules.
1298
1299 If you are not absolutely sure what you are doing, leave this
1300 option alone!
1301
1302 config VMSPLIT_3G
1303 bool "3G/1G user/kernel split"
1304 config VMSPLIT_3G_OPT
1305 depends on !X86_PAE
1306 bool "3G/1G user/kernel split (for full 1G low memory)"
1307 config VMSPLIT_2G
1308 bool "2G/2G user/kernel split"
1309 config VMSPLIT_2G_OPT
1310 depends on !X86_PAE
1311 bool "2G/2G user/kernel split (for full 2G low memory)"
1312 config VMSPLIT_1G
1313 bool "1G/3G user/kernel split"
1314endchoice
1315
1316config PAGE_OFFSET
1317 hex
1318 default 0xB0000000 if VMSPLIT_3G_OPT
1319 default 0x80000000 if VMSPLIT_2G
1320 default 0x78000000 if VMSPLIT_2G_OPT
1321 default 0x40000000 if VMSPLIT_1G
1322 default 0xC0000000
1323 depends on X86_32
1324
1325config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001326 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001327 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001328
1329config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001330 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001331 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001332 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001333 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001334 PAE is required for NX support, and furthermore enables
1335 larger swapspace support for non-overcommit purposes. It
1336 has the cost of more pagetable lookup overhead, and also
1337 consumes more pagetable space per process.
1338
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001339config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001340 def_bool y
1341 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001342
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001343config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001344 def_bool y
1345 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001346
Ingo Molnar10971ab2015-03-05 08:18:23 +01001347config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001348 def_bool y
1349 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001350 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001351 Certain kernel features effectively disable kernel
1352 linear 1 GB mappings (even if the CPU otherwise
1353 supports them), so don't confuse the user by printing
1354 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001355
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001356# Common NUMA Features
1357config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001358 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001359 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001360 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1361 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001362 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001363 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001364
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001365 The kernel will try to allocate memory used by a CPU on the
1366 local memory controller of the CPU and add some more
1367 NUMA awareness to the kernel.
1368
Ingo Molnarc280ea52008-11-08 13:29:45 +01001369 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001370 (or later), AMD Opteron, or EM64T NUMA.
1371
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001372 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001373 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001374
1375 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001376
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001377config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001378 def_bool y
1379 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001380 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001381 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001382 Enable AMD NUMA node topology detection. You should say Y here if
1383 you have a multi processor AMD system. This uses an old method to
1384 read the NUMA configuration directly from the builtin Northbridge
1385 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1386 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001387
1388config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001389 def_bool y
1390 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001391 depends on X86_64 && NUMA && ACPI && PCI
1392 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001393 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001394 Enable ACPI SRAT based node topology detection.
1395
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001396# Some NUMA nodes have memory ranges that span
1397# other nodes. Even though a pfn is valid and
1398# between a node's start and end pfns, it may not
1399# reside on that node. See memmap_init_zone()
1400# for details.
1401config NODES_SPAN_OTHER_NODES
1402 def_bool y
1403 depends on X86_64_ACPI_NUMA
1404
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001405config NUMA_EMU
1406 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001407 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001408 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001409 Enable NUMA emulation. A flat machine will be split
1410 into virtual nodes when booted with "numa=fake=N", where N is the
1411 number of nodes. This is only useful for debugging.
1412
1413config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001414 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001415 range 1 10
1416 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001417 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001418 default "3"
1419 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001420 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001421 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001422 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001423
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001424config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001425 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001426 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001427
1428config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001429 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001430 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001431
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001432config ARCH_FLATMEM_ENABLE
1433 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001434 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001435
1436config ARCH_DISCONTIGMEM_ENABLE
1437 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001438 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001439
1440config ARCH_DISCONTIGMEM_DEFAULT
1441 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001442 depends on NUMA && X86_32
1443
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001444config ARCH_SPARSEMEM_ENABLE
1445 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001446 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001447 select SPARSEMEM_STATIC if X86_32
1448 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1449
Tejun Heo3b166512011-04-01 11:15:12 +02001450config ARCH_SPARSEMEM_DEFAULT
1451 def_bool y
1452 depends on X86_64
1453
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001454config ARCH_SELECT_MEMORY_MODEL
1455 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001456 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001457
1458config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001459 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001460 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001461 help
1462 This option enables a sysfs memory/probe interface for testing.
1463 See Documentation/memory-hotplug.txt for more information.
1464 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001465
Tejun Heo3b166512011-04-01 11:15:12 +02001466config ARCH_PROC_KCORE_TEXT
1467 def_bool y
1468 depends on X86_64 && PROC_KCORE
1469
Avi Kivitya29815a2010-01-10 16:28:09 +02001470config ILLEGAL_POINTER_VALUE
1471 hex
1472 default 0 if X86_32
1473 default 0xdead000000000000 if X86_64
1474
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001475source "mm/Kconfig"
1476
Dan Williams7a678322015-08-19 00:34:34 -04001477config X86_PMEM_LEGACY_DEVICE
1478 bool
1479
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001480config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001481 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001482 depends on PHYS_ADDR_T_64BIT
1483 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001484 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001485 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001486 help
1487 Treat memory marked using the non-standard e820 type of 12 as used
1488 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1489 The kernel will offer these regions to the 'pmem' driver so
1490 they can be used for persistent storage.
1491
1492 Say Y if unsure.
1493
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001494config HIGHPTE
1495 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001496 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001497 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001498 The VM uses one page table entry for each page of physical memory.
1499 For systems with a lot of RAM, this can be wasteful of precious
1500 low memory. Setting this option will put user-space page table
1501 entries in high memory.
1502
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001503config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001504 bool "Check for low memory corruption"
1505 ---help---
1506 Periodically check for memory corruption in low memory, which
1507 is suspected to be caused by BIOS. Even when enabled in the
1508 configuration, it is disabled at runtime. Enable it by
1509 setting "memory_corruption_check=1" on the kernel command
1510 line. By default it scans the low 64k of memory every 60
1511 seconds; see the memory_corruption_check_size and
1512 memory_corruption_check_period parameters in
1513 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001514
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001515 When enabled with the default parameters, this option has
1516 almost no overhead, as it reserves a relatively small amount
1517 of memory and scans it infrequently. It both detects corruption
1518 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001519
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001520 It is, however, intended as a diagnostic tool; if repeatable
1521 BIOS-originated corruption always affects the same memory,
1522 you can use memmap= to prevent the kernel from using that
1523 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001524
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001525config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001526 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001527 depends on X86_CHECK_BIOS_CORRUPTION
1528 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001529 ---help---
1530 Set whether the default state of memory_corruption_check is
1531 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001532
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001533config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001534 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1535 default 64
1536 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001537 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001538 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001539
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001540 The first page contains BIOS data structures that the kernel
1541 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001542
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001543 By default we reserve the first 64K of physical RAM, as a
1544 number of BIOSes are known to corrupt that memory range
1545 during events such as suspend/resume or monitor cable
1546 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001547
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001548 You can set this to 4 if you are absolutely sure that you
1549 trust the BIOS to get all its memory reservations and usages
1550 right. If you know your BIOS have problems beyond the
1551 default 64K area, you can set this to 640 to avoid using the
1552 entire low memory range.
1553
1554 If you have doubts about the BIOS (e.g. suspend/resume does
1555 not work or there's kernel crashes after certain hardware
1556 hotplug events) then you might want to enable
1557 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1558 typical corruption patterns.
1559
1560 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001561
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001562config MATH_EMULATION
1563 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001564 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001565 prompt "Math emulation" if X86_32
1566 ---help---
1567 Linux can emulate a math coprocessor (used for floating point
1568 operations) if you don't have one. 486DX and Pentium processors have
1569 a math coprocessor built in, 486SX and 386 do not, unless you added
1570 a 487DX or 387, respectively. (The messages during boot time can
1571 give you some hints here ["man dmesg"].) Everyone needs either a
1572 coprocessor or this emulation.
1573
1574 If you don't have a math coprocessor, you need to say Y here; if you
1575 say Y here even though you have a coprocessor, the coprocessor will
1576 be used nevertheless. (This behavior can be changed with the kernel
1577 command line option "no387", which comes handy if your coprocessor
1578 is broken. Try "man bootparam" or see the documentation of your boot
1579 loader (lilo or loadlin) about how to pass options to the kernel at
1580 boot time.) This means that it is a good idea to say Y here if you
1581 intend to use this kernel on different machines.
1582
1583 More information about the internals of the Linux math coprocessor
1584 emulation can be found in <file:arch/x86/math-emu/README>.
1585
1586 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1587 kernel, it won't hurt.
1588
1589config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001590 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001591 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001592 ---help---
1593 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1594 the Memory Type Range Registers (MTRRs) may be used to control
1595 processor access to memory ranges. This is most useful if you have
1596 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1597 allows bus write transfers to be combined into a larger transfer
1598 before bursting over the PCI/AGP bus. This can increase performance
1599 of image write operations 2.5 times or more. Saying Y here creates a
1600 /proc/mtrr file which may be used to manipulate your processor's
1601 MTRRs. Typically the X server should use this.
1602
1603 This code has a reasonably generic interface so that similar
1604 control registers on other processors can be easily supported
1605 as well:
1606
1607 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1608 Registers (ARRs) which provide a similar functionality to MTRRs. For
1609 these, the ARRs are used to emulate the MTRRs.
1610 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1611 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1612 write-combining. All of these processors are supported by this code
1613 and it makes sense to say Y here if you have one of them.
1614
1615 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1616 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1617 can lead to all sorts of problems, so it's good to say Y here.
1618
1619 You can safely say Y even if your machine doesn't have MTRRs, you'll
1620 just add about 9 KB to your kernel.
1621
Randy Dunlap7225e752008-07-26 17:54:22 -07001622 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001623
Yinghai Lu95ffa242008-04-29 03:52:33 -07001624config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001625 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001626 prompt "MTRR cleanup support"
1627 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001628 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001629 Convert MTRR layout from continuous to discrete, so X drivers can
1630 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001631
Thomas Gleixneraba37282008-07-15 14:48:48 +02001632 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001633 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001634 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001635
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001636 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001637
1638config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001639 int "MTRR cleanup enable value (0-1)"
1640 range 0 1
1641 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001642 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001643 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001644 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001645
Yinghai Lu12031a62008-05-02 02:40:22 -07001646config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1647 int "MTRR cleanup spare reg num (0-7)"
1648 range 0 7
1649 default "1"
1650 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001651 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001652 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001653 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001654
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001655config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001656 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001657 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001658 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001659 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001660 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001661
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001662 PATs are the modern equivalents of MTRRs and are much more
1663 flexible than MTRRs.
1664
1665 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001666 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001667
1668 If unsure, say Y.
1669
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001670config ARCH_USES_PG_UNCACHED
1671 def_bool y
1672 depends on X86_PAT
1673
H. Peter Anvin628c6242011-07-31 13:59:29 -07001674config ARCH_RANDOM
1675 def_bool y
1676 prompt "x86 architectural random number generator" if EXPERT
1677 ---help---
1678 Enable the x86 architectural RDRAND instruction
1679 (Intel Bull Mountain technology) to generate random numbers.
1680 If supported, this is a high bandwidth, cryptographically
1681 secure hardware random number generator.
1682
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001683config X86_SMAP
1684 def_bool y
1685 prompt "Supervisor Mode Access Prevention" if EXPERT
1686 ---help---
1687 Supervisor Mode Access Prevention (SMAP) is a security
1688 feature in newer Intel processors. There is a small
1689 performance cost if this enabled and turned on; there is
1690 also a small increase in the kernel size if this is enabled.
1691
1692 If unsure, say Y.
1693
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001694config X86_INTEL_MPX
1695 prompt "Intel MPX (Memory Protection Extensions)"
1696 def_bool n
1697 depends on CPU_SUP_INTEL
1698 ---help---
1699 MPX provides hardware features that can be used in
1700 conjunction with compiler-instrumented code to check
1701 memory references. It is designed to detect buffer
1702 overflow or underflow bugs.
1703
1704 This option enables running applications which are
1705 instrumented or otherwise use MPX. It does not use MPX
1706 itself inside the kernel or to protect the kernel
1707 against bad memory references.
1708
1709 Enabling this option will make the kernel larger:
1710 ~8k of kernel text and 36 bytes of data on a 64-bit
1711 defconfig. It adds a long to the 'mm_struct' which
1712 will increase the kernel memory overhead of each
1713 process and adds some branches to paths used during
1714 exec() and munmap().
1715
1716 For details, see Documentation/x86/intel_mpx.txt
1717
1718 If unsure, say N.
1719
Dave Hansen35e97792016-02-12 13:02:00 -08001720config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001721 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001722 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001723 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001724 depends on CPU_SUP_INTEL && X86_64
Dave Hansen284244a2016-02-12 13:02:28 -08001725 ---help---
1726 Memory Protection Keys provides a mechanism for enforcing
1727 page-based protections, but without requiring modification of the
1728 page tables when an application changes protection domains.
1729
1730 For details, see Documentation/x86/protection-keys.txt
1731
1732 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001733
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001734config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001735 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001736 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001737 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001738 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001739 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001740 This enables the kernel to use EFI runtime services that are
1741 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001742
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001743 This option is only useful on systems that have EFI firmware.
1744 In addition, you should use the latest ELILO loader available
1745 at <http://elilo.sourceforge.net> in order to take advantage
1746 of EFI runtime services. However, even with this option, the
1747 resultant kernel should continue to boot on existing non-EFI
1748 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001749
Matt Fleming291f3632011-12-12 21:27:52 +00001750config EFI_STUB
1751 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001752 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001753 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001754 ---help---
1755 This kernel feature allows a bzImage to be loaded directly
1756 by EFI firmware without the use of a bootloader.
1757
Roy Franz4172fe22013-09-22 15:45:25 -07001758 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001759
Matt Fleming7d453ee2014-01-10 18:52:06 +00001760config EFI_MIXED
1761 bool "EFI mixed-mode support"
1762 depends on EFI_STUB && X86_64
1763 ---help---
1764 Enabling this feature allows a 64-bit kernel to be booted
1765 on a 32-bit firmware, provided that your CPU supports 64-bit
1766 mode.
1767
1768 Note that it is not possible to boot a mixed-mode enabled
1769 kernel via the EFI boot stub - a bootloader that supports
1770 the EFI handover protocol must be used.
1771
1772 If unsure, say N.
1773
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001774config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001775 def_bool y
1776 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001777 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001778 This kernel feature is useful for number crunching applications
1779 that may need to compute untrusted bytecode during their
1780 execution. By using pipes or other transports made available to
1781 the process as file descriptors supporting the read/write
1782 syscalls, it's possible to isolate those applications in
1783 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001784 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001785 and the task is only allowed to execute a few safe syscalls
1786 defined by each seccomp mode.
1787
1788 If unsure, say Y. Only embedded should say N here.
1789
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001790source kernel/Kconfig.hz
1791
1792config KEXEC
1793 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001794 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001795 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001796 kexec is a system call that implements the ability to shutdown your
1797 current kernel, and to start another kernel. It is like a reboot
1798 but it is independent of the system firmware. And like a reboot
1799 you can start any kernel with it, not just Linux.
1800
1801 The name comes from the similarity to the exec system call.
1802
1803 It is an ongoing process to be certain the hardware in a machine
1804 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001805 initially work for you. As of this writing the exact hardware
1806 interface is strongly in flux, so no good recommendation can be
1807 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001808
Vivek Goyal74ca3172014-08-29 15:18:46 -07001809config KEXEC_FILE
1810 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001811 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001812 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001813 depends on X86_64
1814 depends on CRYPTO=y
1815 depends on CRYPTO_SHA256=y
1816 ---help---
1817 This is new version of kexec system call. This system call is
1818 file based and takes file descriptors as system call argument
1819 for kernel and initramfs as opposed to list of segments as
1820 accepted by previous system call.
1821
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001822config KEXEC_VERIFY_SIG
1823 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001824 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001825 ---help---
1826 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001827 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001828
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001829 In addition to that option, you need to enable signature
1830 verification for the corresponding kernel image type being
1831 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001832
1833config KEXEC_BZIMAGE_VERIFY_SIG
1834 bool "Enable bzImage signature verification support"
1835 depends on KEXEC_VERIFY_SIG
1836 depends on SIGNED_PE_FILE_VERIFICATION
1837 select SYSTEM_TRUSTED_KEYRING
1838 ---help---
1839 Enable bzImage signature verification support.
1840
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001841config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001842 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001843 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001844 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001845 Generate crash dump after being started by kexec.
1846 This should be normally only set in special crash dump kernels
1847 which are loaded in the main kernel with kexec-tools into
1848 a specially reserved region and then later executed after
1849 a crash by kdump/kexec. The crash dump kernel must be compiled
1850 to a memory address not used by the main kernel or BIOS using
1851 PHYSICAL_START, or it must be built as a relocatable image
1852 (CONFIG_RELOCATABLE=y).
1853 For more details see Documentation/kdump/kdump.txt
1854
Huang Ying3ab83522008-07-25 19:45:07 -07001855config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001856 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001857 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001858 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001859 Jump between original kernel and kexeced kernel and invoke
1860 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001861
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001862config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001863 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001864 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001865 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001866 This gives the physical address where the kernel is loaded.
1867
1868 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1869 bzImage will decompress itself to above physical address and
1870 run from there. Otherwise, bzImage will run from the address where
1871 it has been loaded by the boot loader and will ignore above physical
1872 address.
1873
1874 In normal kdump cases one does not have to set/change this option
1875 as now bzImage can be compiled as a completely relocatable image
1876 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1877 address. This option is mainly useful for the folks who don't want
1878 to use a bzImage for capturing the crash dump and want to use a
1879 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1880 to be specifically compiled to run from a specific memory area
1881 (normally a reserved region) and this option comes handy.
1882
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001883 So if you are using bzImage for capturing the crash dump,
1884 leave the value here unchanged to 0x1000000 and set
1885 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1886 for capturing the crash dump change this value to start of
1887 the reserved region. In other words, it can be set based on
1888 the "X" value as specified in the "crashkernel=YM@XM"
1889 command line boot parameter passed to the panic-ed
1890 kernel. Please take a look at Documentation/kdump/kdump.txt
1891 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001892
1893 Usage of bzImage for capturing the crash dump is recommended as
1894 one does not have to build two kernels. Same kernel can be used
1895 as production kernel and capture kernel. Above option should have
1896 gone away after relocatable bzImage support is introduced. But it
1897 is present because there are users out there who continue to use
1898 vmlinux for dump capture. This option should go away down the
1899 line.
1900
1901 Don't change this unless you know what you are doing.
1902
1903config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001904 bool "Build a relocatable kernel"
1905 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001906 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001907 This builds a kernel image that retains relocation information
1908 so it can be loaded someplace besides the default 1MB.
1909 The relocations tend to make the kernel binary about 10% larger,
1910 but are discarded at runtime.
1911
1912 One use is for the kexec on panic case where the recovery kernel
1913 must live at a different physical address than the primary
1914 kernel.
1915
1916 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1917 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001918 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001919
Kees Cook8ab38202013-10-10 17:18:14 -07001920config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07001921 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07001922 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001923 default n
1924 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07001925 In support of Kernel Address Space Layout Randomization (KASLR),
1926 this randomizes the physical address at which the kernel image
1927 is decompressed and the virtual address where the kernel
1928 image is mapped, as a security feature that deters exploit
1929 attempts relying on knowledge of the location of kernel
1930 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07001931
Baoquan Hee8581e32016-04-20 13:55:43 -07001932 The kernel physical and virtual address can be randomized
1933 from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that
1934 using RANDOMIZE_BASE reduces the memory space available to
1935 kernel modules from 1.5GB to 1GB.)
Kees Cook8ab38202013-10-10 17:18:14 -07001936
Baoquan Hee8581e32016-04-20 13:55:43 -07001937 Entropy is generated using the RDRAND instruction if it is
1938 supported. If RDTSC is supported, its value is mixed into
1939 the entropy pool as well. If neither RDRAND nor RDTSC are
1940 supported, then entropy is read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001941
Baoquan Hee8581e32016-04-20 13:55:43 -07001942 Since the kernel is built using 2GB addressing, and
1943 PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of
1944 entropy is theoretically possible. Currently, with the
1945 default value for PHYSICAL_ALIGN and due to page table
1946 layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits.
Kees Cookda2b6fb2013-12-10 12:27:45 -08001947
Baoquan Hee8581e32016-04-20 13:55:43 -07001948 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1949 time. To enable it, boot with "kaslr" on the kernel command
1950 line (which will also disable hibernation).
Kees Cook6145cfe2013-10-10 17:18:18 -07001951
Baoquan Hee8581e32016-04-20 13:55:43 -07001952 If unsure, say N.
Kees Cook8ab38202013-10-10 17:18:14 -07001953
1954# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001955config X86_NEED_RELOCS
1956 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001957 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001958
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001959config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001960 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001961 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001962 range 0x2000 0x1000000 if X86_32
1963 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001964 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001965 This value puts the alignment restrictions on physical address
1966 where kernel is loaded and run from. Kernel is compiled for an
1967 address which meets above alignment restriction.
1968
1969 If bootloader loads the kernel at a non-aligned address and
1970 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1971 address aligned to above value and run from there.
1972
1973 If bootloader loads the kernel at a non-aligned address and
1974 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1975 load address and decompress itself to the address it has been
1976 compiled for and run from there. The address for which kernel is
1977 compiled already meets above alignment restrictions. Hence the
1978 end result is that kernel runs from a physical address meeting
1979 above alignment restrictions.
1980
Kees Cooka0215062013-07-08 09:15:17 -07001981 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1982 this value must be a multiple of 0x200000.
1983
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001984 Don't change this unless you know what you are doing.
1985
1986config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001987 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10001988 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001989 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001990 Say Y here to allow turning CPUs off and on. CPUs can be
1991 controlled through /sys/devices/system/cpu.
1992 ( Note: power management support will enable this option
1993 automatically on SMP systems. )
1994 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001995
Fenghua Yu80aa1df2012-11-13 11:32:39 -08001996config BOOTPARAM_HOTPLUG_CPU0
1997 bool "Set default setting of cpu0_hotpluggable"
1998 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08001999 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002000 ---help---
2001 Set whether default state of cpu0_hotpluggable is on or off.
2002
2003 Say Y here to enable CPU0 hotplug by default. If this switch
2004 is turned on, there is no need to give cpu0_hotplug kernel
2005 parameter and the CPU0 hotplug feature is enabled by default.
2006
2007 Please note: there are two known CPU0 dependencies if you want
2008 to enable the CPU0 hotplug feature either by this switch or by
2009 cpu0_hotplug kernel parameter.
2010
2011 First, resume from hibernate or suspend always starts from CPU0.
2012 So hibernate and suspend are prevented if CPU0 is offline.
2013
2014 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2015 offline if any interrupt can not migrate out of CPU0. There may
2016 be other CPU0 dependencies.
2017
2018 Please make sure the dependencies are under your control before
2019 you enable this feature.
2020
2021 Say N if you don't want to enable CPU0 hotplug feature by default.
2022 You still can enable the CPU0 hotplug feature at boot by kernel
2023 parameter cpu0_hotplug.
2024
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002025config DEBUG_HOTPLUG_CPU0
2026 def_bool n
2027 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002028 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002029 ---help---
2030 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2031 soon as possible and boots up userspace with CPU0 offlined. User
2032 can online CPU0 back after boot time.
2033
2034 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2035 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2036 compilation or giving cpu0_hotplug kernel parameter at boot.
2037
2038 If unsure, say N.
2039
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002040config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002041 def_bool n
2042 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002043 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002044 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002045 Certain buggy versions of glibc will crash if they are
2046 presented with a 32-bit vDSO that is not mapped at the address
2047 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002048
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002049 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2050 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2051 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2052 the only released version with the bug, but OpenSUSE 9
2053 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002054
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002055 The symptom of the bug is that everything crashes on startup, saying:
2056 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2057
2058 Saying Y here changes the default value of the vdso32 boot
2059 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2060 This works around the glibc bug but hurts performance.
2061
2062 If unsure, say N: if you are compiling your own kernel, you
2063 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002064
Kees Cook3dc33bd2015-08-12 17:55:19 -07002065choice
2066 prompt "vsyscall table for legacy applications"
2067 depends on X86_64
2068 default LEGACY_VSYSCALL_EMULATE
2069 help
2070 Legacy user code that does not know how to find the vDSO expects
2071 to be able to issue three syscalls by calling fixed addresses in
2072 kernel space. Since this location is not randomized with ASLR,
2073 it can be used to assist security vulnerability exploitation.
2074
2075 This setting can be changed at boot time via the kernel command
2076 line parameter vsyscall=[native|emulate|none].
2077
2078 On a system with recent enough glibc (2.14 or newer) and no
2079 static binaries, you can say None without a performance penalty
2080 to improve security.
2081
2082 If unsure, select "Emulate".
2083
2084 config LEGACY_VSYSCALL_NATIVE
2085 bool "Native"
2086 help
2087 Actual executable code is located in the fixed vsyscall
2088 address mapping, implementing time() efficiently. Since
2089 this makes the mapping executable, it can be used during
2090 security vulnerability exploitation (traditionally as
2091 ROP gadgets). This configuration is not recommended.
2092
2093 config LEGACY_VSYSCALL_EMULATE
2094 bool "Emulate"
2095 help
2096 The kernel traps and emulates calls into the fixed
2097 vsyscall address mapping. This makes the mapping
2098 non-executable, but it still contains known contents,
2099 which could be used in certain rare security vulnerability
2100 exploits. This configuration is recommended when userspace
2101 still uses the vsyscall area.
2102
2103 config LEGACY_VSYSCALL_NONE
2104 bool "None"
2105 help
2106 There will be no vsyscall mapping at all. This will
2107 eliminate any risk of ASLR bypass due to the vsyscall
2108 fixed address mapping. Attempts to use the vsyscalls
2109 will be reported to dmesg, so that either old or
2110 malicious userspace programs can be identified.
2111
2112endchoice
2113
Tim Bird516cbf32008-08-12 12:52:36 -07002114config CMDLINE_BOOL
2115 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002116 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002117 Allow for specifying boot arguments to the kernel at
2118 build time. On some systems (e.g. embedded ones), it is
2119 necessary or convenient to provide some or all of the
2120 kernel boot arguments with the kernel itself (that is,
2121 to not rely on the boot loader to provide them.)
2122
2123 To compile command line arguments into the kernel,
2124 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002125 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002126
2127 Systems with fully functional boot loaders (i.e. non-embedded)
2128 should leave this option set to 'N'.
2129
2130config CMDLINE
2131 string "Built-in kernel command string"
2132 depends on CMDLINE_BOOL
2133 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002134 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002135 Enter arguments here that should be compiled into the kernel
2136 image and used at boot time. If the boot loader provides a
2137 command line at boot time, it is appended to this string to
2138 form the full kernel command line, when the system boots.
2139
2140 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2141 change this behavior.
2142
2143 In most cases, the command line (whether built-in or provided
2144 by the boot loader) should specify the device for the root
2145 file system.
2146
2147config CMDLINE_OVERRIDE
2148 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002149 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002150 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002151 Set this option to 'Y' to have the kernel ignore the boot loader
2152 command line, and use ONLY the built-in command line.
2153
2154 This is used to work around broken boot loaders. This should
2155 be set to 'N' under normal conditions.
2156
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002157config MODIFY_LDT_SYSCALL
2158 bool "Enable the LDT (local descriptor table)" if EXPERT
2159 default y
2160 ---help---
2161 Linux can allow user programs to install a per-process x86
2162 Local Descriptor Table (LDT) using the modify_ldt(2) system
2163 call. This is required to run 16-bit or segmented code such as
2164 DOSEMU or some Wine programs. It is also used by some very old
2165 threading libraries.
2166
2167 Enabling this feature adds a small amount of overhead to
2168 context switches and increases the low-level kernel attack
2169 surface. Disabling it removes the modify_ldt(2) system call.
2170
2171 Saying 'N' here may make sense for embedded or server kernels.
2172
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002173source "kernel/livepatch/Kconfig"
2174
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002175endmenu
2176
2177config ARCH_ENABLE_MEMORY_HOTPLUG
2178 def_bool y
2179 depends on X86_64 || (X86_32 && HIGHMEM)
2180
Gary Hade35551052008-10-31 10:52:03 -07002181config ARCH_ENABLE_MEMORY_HOTREMOVE
2182 def_bool y
2183 depends on MEMORY_HOTPLUG
2184
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002185config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002186 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002187 depends on NUMA
2188
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002189config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2190 def_bool y
2191 depends on X86_64 || X86_PAE
2192
Naoya Horiguchic177c812014-06-04 16:05:35 -07002193config ARCH_ENABLE_HUGEPAGE_MIGRATION
2194 def_bool y
2195 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2196
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002197menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002198
2199config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002200 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002201 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002202
2203source "kernel/power/Kconfig"
2204
2205source "drivers/acpi/Kconfig"
2206
Feng Tangefafc8b2009-08-14 15:23:29 -04002207source "drivers/sfi/Kconfig"
2208
Andi Kleena6b68072008-01-30 13:32:49 +01002209config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002210 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002211 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002212
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002213menuconfig APM
2214 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002215 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002216 ---help---
2217 APM is a BIOS specification for saving power using several different
2218 techniques. This is mostly useful for battery powered laptops with
2219 APM compliant BIOSes. If you say Y here, the system time will be
2220 reset after a RESUME operation, the /proc/apm device will provide
2221 battery status information, and user-space programs will receive
2222 notification of APM "events" (e.g. battery status change).
2223
2224 If you select "Y" here, you can disable actual use of the APM
2225 BIOS by passing the "apm=off" option to the kernel at boot time.
2226
2227 Note that the APM support is almost completely disabled for
2228 machines with more than one CPU.
2229
2230 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002231 and more information, read <file:Documentation/power/apm-acpi.txt>
2232 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002233 <http://www.tldp.org/docs.html#howto>.
2234
2235 This driver does not spin down disk drives (see the hdparm(8)
2236 manpage ("man 8 hdparm") for that), and it doesn't turn off
2237 VESA-compliant "green" monitors.
2238
2239 This driver does not support the TI 4000M TravelMate and the ACER
2240 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2241 desktop machines also don't have compliant BIOSes, and this driver
2242 may cause those machines to panic during the boot phase.
2243
2244 Generally, if you don't have a battery in your machine, there isn't
2245 much point in using this driver and you should say N. If you get
2246 random kernel OOPSes or reboots that don't seem to be related to
2247 anything, try disabling/enabling this option (or disabling/enabling
2248 APM in your BIOS).
2249
2250 Some other things you should try when experiencing seemingly random,
2251 "weird" problems:
2252
2253 1) make sure that you have enough swap space and that it is
2254 enabled.
2255 2) pass the "no-hlt" option to the kernel
2256 3) switch on floating point emulation in the kernel and pass
2257 the "no387" option to the kernel
2258 4) pass the "floppy=nodma" option to the kernel
2259 5) pass the "mem=4M" option to the kernel (thereby disabling
2260 all but the first 4 MB of RAM)
2261 6) make sure that the CPU is not over clocked.
2262 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2263 8) disable the cache from your BIOS settings
2264 9) install a fan for the video card or exchange video RAM
2265 10) install a better fan for the CPU
2266 11) exchange RAM chips
2267 12) exchange the motherboard.
2268
2269 To compile this driver as a module, choose M here: the
2270 module will be called apm.
2271
2272if APM
2273
2274config APM_IGNORE_USER_SUSPEND
2275 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002276 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002277 This option will ignore USER SUSPEND requests. On machines with a
2278 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2279 series notebooks, it is necessary to say Y because of a BIOS bug.
2280
2281config APM_DO_ENABLE
2282 bool "Enable PM at boot time"
2283 ---help---
2284 Enable APM features at boot time. From page 36 of the APM BIOS
2285 specification: "When disabled, the APM BIOS does not automatically
2286 power manage devices, enter the Standby State, enter the Suspend
2287 State, or take power saving steps in response to CPU Idle calls."
2288 This driver will make CPU Idle calls when Linux is idle (unless this
2289 feature is turned off -- see "Do CPU IDLE calls", below). This
2290 should always save battery power, but more complicated APM features
2291 will be dependent on your BIOS implementation. You may need to turn
2292 this option off if your computer hangs at boot time when using APM
2293 support, or if it beeps continuously instead of suspending. Turn
2294 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2295 T400CDT. This is off by default since most machines do fine without
2296 this feature.
2297
2298config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002299 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002300 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002301 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002302 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2303 On some machines, this can activate improved power savings, such as
2304 a slowed CPU clock rate, when the machine is idle. These idle calls
2305 are made after the idle loop has run for some length of time (e.g.,
2306 333 mS). On some machines, this will cause a hang at boot time or
2307 whenever the CPU becomes idle. (On machines with more than one CPU,
2308 this option does nothing.)
2309
2310config APM_DISPLAY_BLANK
2311 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002312 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002313 Enable console blanking using the APM. Some laptops can use this to
2314 turn off the LCD backlight when the screen blanker of the Linux
2315 virtual console blanks the screen. Note that this is only used by
2316 the virtual console screen blanker, and won't turn off the backlight
2317 when using the X Window system. This also doesn't have anything to
2318 do with your VESA-compliant power-saving monitor. Further, this
2319 option doesn't work for all laptops -- it might not turn off your
2320 backlight at all, or it might print a lot of errors to the console,
2321 especially if you are using gpm.
2322
2323config APM_ALLOW_INTS
2324 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002325 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002326 Normally we disable external interrupts while we are making calls to
2327 the APM BIOS as a measure to lessen the effects of a badly behaving
2328 BIOS implementation. The BIOS should reenable interrupts if it
2329 needs to. Unfortunately, some BIOSes do not -- especially those in
2330 many of the newer IBM Thinkpads. If you experience hangs when you
2331 suspend, try setting this to Y. Otherwise, say N.
2332
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002333endif # APM
2334
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002335source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002336
2337source "drivers/cpuidle/Kconfig"
2338
Andy Henroid27471fd2008-10-09 11:45:22 -07002339source "drivers/idle/Kconfig"
2340
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002341endmenu
2342
2343
2344menu "Bus options (PCI etc.)"
2345
2346config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002347 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002348 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002349 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002350 Find out whether you have a PCI motherboard. PCI is the name of a
2351 bus system, i.e. the way the CPU talks to the other stuff inside
2352 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2353 VESA. If you have PCI, say Y, otherwise N.
2354
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002355choice
2356 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002357 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002358 default PCI_GOANY
2359 ---help---
2360 On PCI systems, the BIOS can be used to detect the PCI devices and
2361 determine their configuration. However, some old PCI motherboards
2362 have BIOS bugs and may crash if this is done. Also, some embedded
2363 PCI-based systems don't have any BIOS at all. Linux can also try to
2364 detect the PCI hardware directly without using the BIOS.
2365
2366 With this option, you can specify how Linux should detect the
2367 PCI devices. If you choose "BIOS", the BIOS will be used,
2368 if you choose "Direct", the BIOS won't be used, and if you
2369 choose "MMConfig", then PCI Express MMCONFIG will be used.
2370 If you choose "Any", the kernel will try MMCONFIG, then the
2371 direct access method and falls back to the BIOS if that doesn't
2372 work. If unsure, go with the default, which is "Any".
2373
2374config PCI_GOBIOS
2375 bool "BIOS"
2376
2377config PCI_GOMMCONFIG
2378 bool "MMConfig"
2379
2380config PCI_GODIRECT
2381 bool "Direct"
2382
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002383config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002384 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002385 depends on OLPC
2386
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002387config PCI_GOANY
2388 bool "Any"
2389
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002390endchoice
2391
2392config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002393 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002394 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002395
2396# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2397config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002398 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002399 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002400
2401config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002402 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002403 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002404
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002405config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002406 def_bool y
2407 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002408
Alex Nixonb5401a92010-03-18 16:31:34 -04002409config PCI_XEN
2410 def_bool y
2411 depends on PCI && XEN
2412 select SWIOTLB_XEN
2413
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002414config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002415 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002416 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002417
2418config PCI_MMCONFIG
2419 bool "Support mmconfig PCI config space access"
2420 depends on X86_64 && PCI && ACPI
2421
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002422config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002423 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002424 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002425 help
2426 Read the PCI windows out of the CNB20LE host bridge. This allows
2427 PCI hotplug to work on systems with the CNB20LE chipset which do
2428 not have ACPI.
2429
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002430 There's no public spec for this chipset, and this functionality
2431 is known to be incomplete.
2432
2433 You should say N unless you know you need this.
2434
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002435source "drivers/pci/Kconfig"
2436
David Rientjes1c00f012011-03-22 16:34:59 -07002437# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002438config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002439 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2440 default y
2441 help
2442 Enables ISA-style DMA support for devices requiring such controllers.
2443 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002444
Linus Torvalds51e68d02016-05-21 10:25:19 -07002445if X86_32
2446
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002447config ISA
2448 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002449 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002450 Find out whether you have ISA slots on your motherboard. ISA is the
2451 name of a bus system, i.e. the way the CPU talks to the other stuff
2452 inside your box. Other bus systems are PCI, EISA, MicroChannel
2453 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2454 newer boards don't support it. If you have ISA, say Y, otherwise N.
2455
2456config EISA
2457 bool "EISA support"
2458 depends on ISA
2459 ---help---
2460 The Extended Industry Standard Architecture (EISA) bus was
2461 developed as an open alternative to the IBM MicroChannel bus.
2462
2463 The EISA bus provided some of the features of the IBM MicroChannel
2464 bus while maintaining backward compatibility with cards made for
2465 the older ISA bus. The EISA bus saw limited use between 1988 and
2466 1995 when it was made obsolete by the PCI bus.
2467
2468 Say Y here if you are building a kernel for an EISA-based machine.
2469
2470 Otherwise, say N.
2471
2472source "drivers/eisa/Kconfig"
2473
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002474config SCx200
2475 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002476 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002477 This provides basic support for National Semiconductor's
2478 (now AMD's) Geode processors. The driver probes for the
2479 PCI-IDs of several on-chip devices, so its a good dependency
2480 for other scx200_* drivers.
2481
2482 If compiled as a module, the driver is named scx200.
2483
2484config SCx200HR_TIMER
2485 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002486 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002487 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002488 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002489 This driver provides a clocksource built upon the on-chip
2490 27MHz high-resolution timer. Its also a workaround for
2491 NSC Geode SC-1100's buggy TSC, which loses time when the
2492 processor goes idle (as is done by the scheduler). The
2493 other workaround is idle=poll boot option.
2494
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002495config OLPC
2496 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002497 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002498 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002499 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002500 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002501 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002502 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002503 Add support for detecting the unique features of the OLPC
2504 XO hardware.
2505
Daniel Drakea3128582011-06-25 17:34:10 +01002506config OLPC_XO1_PM
2507 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002508 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002509 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002510 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002511 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002512
Daniel Drakecfee9592011-06-25 17:34:17 +01002513config OLPC_XO1_RTC
2514 bool "OLPC XO-1 Real Time Clock"
2515 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2516 ---help---
2517 Add support for the XO-1 real time clock, which can be used as a
2518 programmable wakeup source.
2519
Daniel Drake7feda8e2011-06-25 17:34:12 +01002520config OLPC_XO1_SCI
2521 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002522 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002523 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002524 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002525 select GPIO_CS5535
2526 select MFD_CORE
2527 ---help---
2528 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002529 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002530 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002531 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002532 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002533 - AC adapter status updates
2534 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002535
Daniel Drakea0f30f52011-06-25 17:34:18 +01002536config OLPC_XO15_SCI
2537 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002538 depends on OLPC && ACPI
2539 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002540 ---help---
2541 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2542 - EC-driven system wakeups
2543 - AC adapter status updates
2544 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002545
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002546config ALIX
2547 bool "PCEngines ALIX System Support (LED setup)"
2548 select GPIOLIB
2549 ---help---
2550 This option enables system support for the PCEngines ALIX.
2551 At present this just sets up LEDs for GPIO control on
2552 ALIX2/3/6 boards. However, other system specific setup should
2553 get added here.
2554
2555 Note: You must still enable the drivers for GPIO and LED support
2556 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2557
2558 Note: You have to set alix.force=1 for boards with Award BIOS.
2559
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002560config NET5501
2561 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2562 select GPIOLIB
2563 ---help---
2564 This option enables system support for the Soekris Engineering net5501.
2565
Philip A. Prindeville31970592012-01-14 01:45:39 -07002566config GEOS
2567 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2568 select GPIOLIB
2569 depends on DMI
2570 ---help---
2571 This option enables system support for the Traverse Technologies GEOS.
2572
Vivien Didelot7d029122013-01-04 16:18:14 -05002573config TS5500
2574 bool "Technologic Systems TS-5500 platform support"
2575 depends on MELAN
2576 select CHECK_SIGNATURE
2577 select NEW_LEDS
2578 select LEDS_CLASS
2579 ---help---
2580 This option enables system support for the Technologic Systems TS-5500.
2581
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002582endif # X86_32
2583
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002584config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002585 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002586 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002587
2588source "drivers/pcmcia/Kconfig"
2589
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002590config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002591 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002592 depends on PCI
2593 default n
2594 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002595 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002596 infrastructure code to support RapidIO interconnect devices.
2597
2598source "drivers/rapidio/Kconfig"
2599
David Herrmanne3263ab2013-08-02 14:05:22 +02002600config X86_SYSFB
2601 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2602 help
2603 Firmwares often provide initial graphics framebuffers so the BIOS,
2604 bootloader or kernel can show basic video-output during boot for
2605 user-guidance and debugging. Historically, x86 used the VESA BIOS
2606 Extensions and EFI-framebuffers for this, which are mostly limited
2607 to x86.
2608 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2609 framebuffers so the new generic system-framebuffer drivers can be
2610 used on x86. If the framebuffer is not compatible with the generic
2611 modes, it is adverticed as fallback platform framebuffer so legacy
2612 drivers like efifb, vesafb and uvesafb can pick it up.
2613 If this option is not selected, all system framebuffers are always
2614 marked as fallback platform framebuffers as usual.
2615
2616 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2617 not be able to pick up generic system framebuffers if this option
2618 is selected. You are highly encouraged to enable simplefb as
2619 replacement if you select this option. simplefb can correctly deal
2620 with generic system framebuffers. But you should still keep vesafb
2621 and others enabled as fallback if a system framebuffer is
2622 incompatible with simplefb.
2623
2624 If unsure, say Y.
2625
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002626endmenu
2627
2628
2629menu "Executable file formats / Emulations"
2630
2631source "fs/Kconfig.binfmt"
2632
2633config IA32_EMULATION
2634 bool "IA32 Emulation"
2635 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002636 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002637 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002638 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002639 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002640 Include code to run legacy 32-bit programs under a
2641 64-bit kernel. You should likely turn this on, unless you're
2642 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002643
2644config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002645 tristate "IA32 a.out support"
2646 depends on IA32_EMULATION
2647 ---help---
2648 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002649
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002650config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002651 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002652 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002653 ---help---
2654 Include code to run binaries for the x32 native 32-bit ABI
2655 for 64-bit processors. An x32 process gets access to the
2656 full 64-bit register file and wide data path while leaving
2657 pointers at 32 bits for smaller memory footprint.
2658
2659 You will need a recent binutils (2.22 or later) with
2660 elf32_x86_64 support enabled to compile a kernel with this
2661 option set.
2662
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002663config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002664 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002665 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002666
Jan Beulich3120e252012-09-10 12:41:45 +01002667if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002668config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002669 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002670
2671config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002672 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002673 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002674
David Howellsee009e4a02011-03-07 15:06:20 +00002675config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002676 def_bool y
2677 depends on KEYS
2678endif
David Howellsee009e4a02011-03-07 15:06:20 +00002679
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002680endmenu
2681
2682
Keith Packarde5beae12008-11-03 18:21:45 +01002683config HAVE_ATOMIC_IOMAP
2684 def_bool y
2685 depends on X86_32
2686
Alessandro Rubini4692d772012-04-04 19:39:58 +02002687config X86_DEV_DMA_OPS
2688 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002689 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002690
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002691config X86_DMA_REMAP
2692 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002693 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002694
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002695config PMC_ATOM
2696 def_bool y
2697 depends on PCI
2698
Keith Busch185a3832016-01-12 13:18:10 -07002699config VMD
2700 depends on PCI_MSI
2701 tristate "Volume Management Device Driver"
2702 default N
2703 ---help---
2704 Adds support for the Intel Volume Management Device (VMD). VMD is a
2705 secondary PCI host bridge that allows PCI Express root ports,
2706 and devices attached to them, to be removed from the default
2707 PCI domain and placed within the VMD domain. This provides
2708 more bus resources than are otherwise possible with a
2709 single domain. If you know your system provides one of these and
2710 has devices attached to it, say Y; if you are not sure, say N.
2711
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002712source "net/Kconfig"
2713
2714source "drivers/Kconfig"
2715
2716source "drivers/firmware/Kconfig"
2717
2718source "fs/Kconfig"
2719
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002720source "arch/x86/Kconfig.debug"
2721
2722source "security/Kconfig"
2723
2724source "crypto/Kconfig"
2725
Avi Kivityedf88412007-12-16 11:02:48 +02002726source "arch/x86/kvm/Kconfig"
2727
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002728source "lib/Kconfig"